Sherwood Engineering HF Test Results

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Whitney Horton
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1 Sherwood Engineering HF Test Results Sample #1 Model IC-R8600 Serial # Test Date: 11/02, 09 & 18 / 2017 Model IC-R8600 Serial # Test Date: 11/15/2017 Note: Data is from sample #1 unless noted as sample #2 IF BW / -60, Hz / Ultimate db IF BW /-60, Hz / Ultimate db Front End Selectivity (A F) First IF rejection +/- khz db Sample #1 Lab #2 Lab #1 Dynamic Range, 20m, Preamp OFF, IP+ OFF Dynamic Range 20 khz 88 db 88 db Dynamic Range 10 khz 88 db 88 db Dynamic Range 5 khz 88 db 88 db Dynamic Range 2 khz 88 db 88 db Dynamic Range, 20m, Preamp OFF, IP+ ON Dynamic Range 20 khz 109 db 109 db Dynamic Range 10 khz 108 db 109 db Dynamic Range 5 khz 108 db 108 db Dynamic Range 2 khz 105 db 107 db Dynamic Range of radio, Preamp OFF, IP+ OFF Dynamic Range 20 khz 78 db Dynamic Range 10 khz 78 db Dynamic Range 5 khz 78 db Dynamic Range 2 khz 78 db Dynamic Range of radio, Preamp OFF, IP+ ON Dynamic Range 20 khz 98 db Dynamic Range 10 khz 97.5 db Dynamic Range 5 khz 97.5 db Dynamic Range 2 khz 97.5 db

2 Blocking above noise floor, 1uV 100 khz, AGC On, -7 dbm Blocking occurs at -7 dbm when OVF lights. Phase noise performance, 20m RMDR /Hz Phase noise (normalized) at 2.5 khz spacing: 111 db 138 Phase noise (normalized) at 5 khz spacing: 114 db 141 Phase noise (normalized) at 10 khz spacing: 117 db 144 Phase noise (normalized) at 20 khz spacing: 119 db 146 Phase noise (normalized) at 30 khz spacing: 120 db 147 Phase noise (normalized) at 40 khz spacing: 120 db 147 Phase noise (normalized) at 50 khz spacing: 121 db 148 Phase noise (normalized) at 80 khz spacing: 122 db 149 Phase noise (normalized) at 100 khz spacing: OVF OVF Phase noise (normalized) at 200 khz spacing: Phase noise (normalized) at 300 khz spacing: Phase noise (normalized) at 400 khz spacing: Phase noise (normalized) at 500 khz spacing: Noise floor, SSB bandwidth 14 MHz, Preamp OFF, IP+ OFF -124 dbm Noise floor, SSB bandwidth 14 MHz, Preamp ON, IP+ OFF -135 dbm Noise floor, SSB bandwidth 14 MHz, Preamp OFF, IP+ ON -123 dbm Sensitivity SSB at 14 MHz, Preamp OFF, IP+ OFF 0.40 uv Sensitivity SSB at 14 MHz, Preamp ON, IP+ OFF 0.12 uv Sensitivity SSB at 14 MHz, Preamp OFF, IP+ ON 0.49 uv Sample #1 Noise floor, 500 Hz, 14.2 MHz, Preamp OFF, IP+ OFF -131 dbm Noise floor, 500 Hz, 14.2 MHz, Preamp ON, IP+ OFF -142 dbm Noise floor, 500 Hz, 14.2 MHz, Preamp OFF, IP+ ON -130 dbm Noise floor, 500 Hz, 14.2 MHz, Preamp OFF, IP+ OFF -132 dbm Noise floor, 500 Hz, 14.2 MHz, Preamp ON, IP+ OFF -142 dbm Noise floor, 500 Hz, 14.2 MHz, Preamp OFF, IP+ ON dbm

3 VHF and UHF measurements sample #1, sample #2 when noted: #1 #2 Value Noise floor, 500 Hz, MHz, Preamp OFF, IP+ ON dbm Noise floor, 500 Hz, MHz, Preamp ON, IP+ ON dbm Noise floor, 500 Hz, 440 MHz, Preamp OFF, IP+ ON dbm Noise floor, 500 Hz, 440 MHz, Preamp ON, IP+ ON dbm Noise floor, 500 Hz, MHz, Preamp OFF, IP+ ON dbm Noise floor, 500 Hz, MHz, Preamp OFF, IP+ ON dbm Noise floor, 500 Hz, MHz, Preamp ON, IP+ ON dbm Signal for S9, Preamp OFF -72 dbm 53 uv Signal for S9, Preamp ON -83 dbm 15 uv S9 and below, 1 S unit = 3.5 db Signal in dbm instead of S units Absolute accuracy within 1 db. Linearity within 1 db Range: -120 dbm to 0 dbm preamp OFF, -130 dbm to 0 db preamp ON Gain of preamp: 10 db AGC threshold at 3 db, Preamp OFF 2.4 uv AGC threshold at 3 db, Preamp ON 0.67 uv RMDR in db on VHF and UHF bands Sample # #1 #2 #1 #2 #1 #1 khz offset 2m 2m 70cm 70cm 28cm 23cm Dynamic Range in db VHF and UHF, third-order DR3. (* = phase noise limited) khz offset 2m 70cm 28 cm 23cm * 82* 79* 10 84* 81* 82* 79* 5 84* 81* 82* 78* 2 82* 78* 78* 74*

4 Note: 20 khz DR3 measured at 19 khz due to spurious at 20 khz spacing when driven hard enough to overcome reciprocal mixing noise. General comments: The R8600 is very easy to use, having an interface similar to the IC Frequency entry is quickly entered by touching a MHz digit, using the touch screen, digits and decimal point if desired, plus enter. VHF/UHF dynamic range (DR3) and reciprocal mixing (RMDR) wide-spaced performance is similar to the IC Close-in, however, the performance is significantly better. HF performance 10 khz 30 MHz is state-of-the-art. VHF/UHF Dynamic range is dominated by RMDR limitations. While the synthesized conversion local oscillators (LOs) are cleaner close-in than past HF to UHF radios, the dramatic improvement observed at HF through 6m is not yet available at VHF and UHF. Looking forward in respect to the IC-9700 concept radio shown in Japan recently, the question would appear to be whether the 9700 will be general coverage or ham band only. If ham band only, it is conceivable that cleaner fixed-frequency conversion oscillators could mix down to HF direct sampling frequencies and provide an additional 10 to 20-dB improvement. Comments on sample #2, and other published data Measurements by Adam Farson, VA7OJ and the ARRL were lower than sample #1. Mike Frye, KM6AB, was kind enough to supply sample #2 on a loaner basis. Sample #1 has been retested to confirm the 20 meter data. See a few paragraphs below. Dynamic range had very minimal variation with signal spacing, as is normal with a direct-sampling radio. The following table lists the current data sets at 20 khz spacing in a 20 khz bandwidth Data Set DR3 IP+ OFF DR3 IP+ ON Sherwood sample #1 88 db 109 db Sherwood sample #2 78 db 98 db Farson 71 db* 95 db* ARRL 60 db 103 db Sherwood IC db 103 db (For comparison) * (Date was at 2 khz spacing)

5 The data scatter on the direct-sampling frequencies (10 khz to 30 MHz) is more than we have observed in the past on different samples of the IC A full dynamic-range test on 20 meters, with and without IP+, was run again on sample #1 at my second lab, noted as lab #2 in the report above. The equipment is identical, except a 2-port hybrid combiner was used instead of a 4-port combiner. The HP generators are the same low phase noise 8642A model. The Mini-Circuits buffer amps, in-line pads and 15-MHz low-pass filters are also the same. The performance run at lab #2 on sample #1 is virtually identical to data taken at lab #1. At this point, the only conclusion I can make is there are minor variations in production samples of the ADC used in the receiver. I do not consider this a significant problem. With IP+ ON, we are splitting hairs in respect to a 100 db dynamic-range radio. IP+ in the R8600 only degrades receiver noise floor between 1 and 1.5 db. On the other hand, the IC-7300 demonstrates a noise-floor degradation in the range of 11 to 13 db with IP+ ON. Considering the price of its predecessors, the R9000 or R9500, the R8600 has many improved features at a fraction of the cost of the earlier units. In addition, the receiver is quite small, and runs cool. The spectrum scope, while small, has greatly improved resolution compared to legacy Icom radios. Since the R8600 runs on an external 13.8 volt supply, the receiver could be easily operated in a mobile or portable environment. Neither of the Icom power supplies were tested, as both R8600 samples were run off of commercial HP or Astron linear regulated power supplies. Combined Rev D

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